This invention relates to ball throwing devices, and more particularly to such devices which are adjustable to accommodate the throwing of balls of different diameters.
Applicant's earlier U.S. Pat. No. 3,774,584 describes a ball throwing device in which a pair of rotary wheels are independently adjustable in speed to achieve the throwing of a ball with wide variations in velocity and curvature. However, the device is not adjustable to accommodate balls of different diameters and therefore a separate device is required for each different diameter ball. This requirement imposes a significant added cost for those, such as schools, who have need for such devices, for example, for batting and fielding practice and training both in baseball and in softball.